Foldable bed assembly and method of folding the dame

ABSTRACT

A foldable bed assembly includes a bed frame unit having support frames and wing support members retractably located at lateral side of the support frames correspondingly. A bed board unit put on the bed frame unit for putting on a mattress. The bed board unit includes main boards and wing boards are foldably located at lateral side of the main boards correspondingly. When the bed frame unit and the bed board unit are expanded, the wing support members respectively support the underside of the wing boards. A method for folding the foldable bed assembly includes folding the wing boards to the main boards, retracting the wing support members into the support frames, and folding the support frames completely.

CROSS REFERENCE TO RELATED APPLICATIONS

This non-provisional application claims priority under 35 U.S.C. 119(a) on Patent Application No. 111200754 filed in Taiwan on Jan. 19, 2022, the entire contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION 1. Fields of the invention

The present disclosure relates to a foldable bed assembly and, in particular, to a foldable bed assembly with bed frame unit and the bed board unit are pivotable to reduce the volume that the foldable bed assembly occupies so as to reduce the packaging space and transportation space required for shipment.

2. Descriptions of Related Art

In order to solve the shortcomings of a larger storage space or freight space is required, and a higher freight cost to the conventional bed frame assembly which does not include a proper folding mechanism so that a foldable bed assembly becomes one of solutions adopted by the industry to solve the above-mentioned deficiencies. The conventional foldable bed frame is composed of two main support frames that are pivotally connected to each other, and can be folded relative to each other along the longitudinal direction of the folding bed frame. A mattress is put on the two main support frames to form a basic structure of a foldable bed. When storing or transporting it, the two main support frames are folded to saves storage or transportation space required.

Taiwanese Utility patent No. M621470 discloses a foldable bend frame assembly and includes a first frame unit, a second frame unit and two hinge units. The hinge units are used for pivoting the first frame unit and the second frame unit, and each hinge unit includes a hinge piece which has two spaced apart connecting walls, and a bottom wall is connected to one end of the connecting walls. The connecting wall has a first pivot portion pivotally connected to the corresponding first end portion, and a second pivot portion opposite to the first pivot portion and pivotably connected to the corresponding second end portion. The second frame unit is folded relative to the first frame unit between an unfolded position and a folded position. However, the patent does not have lateral folding function to the end wing support and the end wing bed board. Therefore, the bed frame and the bed board cannot be folded to each other, and the volume of the folded status of the bed frame assembly cannot be further reduced, which increases the transportation cost.

US201800254 discloses a folding bed frame and includes two symmetrically arranged bed frame units which are pivotably connected to each other by hinges. The bed frame unit further includes a plurality of first support rods pivotably connected with the bed frame unit by hinges. The direction that the plurality of first support rods are folded is perpendicular to the direction that the bed frame unit is folded.

US2020205576 discloses a folding bed frame and a bed board put on the bed frame. The bed frame includes a first frame unit and a second frame unit arranged side by side and pivotally connected to each other. The bed board includes a first board unit fixedly located on the first frame unit, and a second board unit fixedly located on the second bed frame unit. Each of the first panel unit and the second panel unit includes one or more panel elements. Each panel element includes a substrate, a sponge layer and a cover. The base plate is located on the first or second frame unit. The sponge layer is arranged on the base material, and the cover layer is arranged on the sponge layer.

US2021337976 discloses a transportable and foldable bed frame, and includes a base including a first frame having a bottom and a top, a second frame has a bottom and a top, and a connector pivotally connecting the second frame to the first frame. The first frame and the second frame selectively pivot relative to each other about a pivot, such that the first frame and the second frame selectively pivot relative to each other between the expanded position and the unfolded position. The top of the first frame and the second frame are substantially coplanar and adapted to support the mattress and to close the folded position. The bottom is folded and the top of the second frame covers the top of the first frame.

US2009249545 discloses a portable and foldable bed frame, and includes a triangular support plate installed at the joint between the rotating rod of the rotating support rod and the connecting rod, so as to enhance the supporting strength of the rotating support rod. The width of the fixed support rod is twice of the width of the bed frame. A contact unit is provided between the fixed plate and the fixed support rod, so as to obtain a stable engagement of the fixed support rod. A foldable spring is located between the lower cross bar of the rod and the outer frame of the bed frame, so that the bed can be conveniently folded.

Each of the U.S. Patented bed assemblies mentioned above is able to be folded along the longitudinal direction, however, none of the four bed assemblies provides wing part wing support members, and none of the four bed assemblies provides the features of foldable wing bed board transversely. In other words, the bed board and bed frame cannot be folded transversely to further reduce the storage space and transportation space, and that will increase the transportation cost.

The present invention intends to provide a foldable bed assembly to eliminate the shortcomings mentioned above.

SUMMARY OF THE INVENTION

The present invention relates to a foldable bed assembly that wherein the bed frame unit and the bed board unit are pivotable to reduce the volume that the foldable bed assembly occupies so as to reduce the packaging space and transportation space required for shipment. The foldable bed assembly comprises a bed frame unit having multiple support frames which are foldable with respect to each other along the longitudinal direction of the foldable bed assembly. Multiple wing support members are connected to the bed frame unit and located in a row along the longitudinal direction of the foldable bed assembly. The multiple wing support members are respectively located at least one lateral side of the support frames corresponding thereto. The multiple wing support members are retractably located along the transversal direction of the foldable bed assembly. The longitudinal direction of the foldable bed assembly is perpendicular to the transversal direction of the foldable bed assembly. A bed board unit is put on the bed frame unit and includes multiple main boards which are foldable with respect to each other along the longitudinal direction of the foldable bed assembly. The bed board unit includes multiple wing boards which are located in a row along the longitudinal direction of the foldable bed assembly. The multiple wing boards are respectively located at least one lateral side of the multiple main boards corresponding thereto. The wing boards are foldable with respect to the main boards along the transversal direction of the foldable bed assembly. When the bed frame unit and the bed board unit are expanded, the multiple support frames support undersides of the multiple main boards correspondingly, and the multiple wing support members support undersides of the multiple wing boards correspondingly.

The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view of the foldable bed assembly of the present invention;

FIG. 2 is a perspective view to show the bed frame unit of the present invention, wherein the wing support members are extended;

FIG. 3 is a perspective view to show that the bed frame unit and the bed board unit of the present invention are expanded;

FIG. 4 shows that one of the wing boards is folded toward the main board;

FIG. 5 shows that all of the wing boards are folded toward the main boards;

FIG. 6 shows that all of the wing boards on one end of the foldable bed assembly are folded toward the main boards;

FIG. 7 shows that the bed frame unit and the bed board unit both are folded;

FIG. 8 is a top view of the folded status shown in FIG. 7 ;

FIG. 9 shows that the wing support member is retracted into the transport tube;

FIG. 10 shows that the wing support member extends out from the transport tube, and

FIG. 11 shows that the hinge member is a strip connected between the main board and the wing board.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 1 to 8 , the foldable bed assembly of the present invention comprises a bed frame unit 10 and a bed board unit 20. The bed frame unit 10 includes multiple support frames 11. The multiple support frames 11 are foldable with respect to each other along a longitudinal direction “L” of the foldable bed assembly. Multiple wing support members 12 are connected to the bed frame unit 10 and located in a row along the longitudinal direction “L” of the foldable bed assembly. The multiple wing support members 12 respectively located at least one lateral side of the support frames 11 corresponding thereto, and the multiple wing support members 12 are retractably located along a transversal direction “T” of the foldable bed assembly. The longitudinal direction “L” of the foldable bed assembly is perpendicular to the transversal direction “T” of the foldable bed assembly. In this embodiment, the wing support members 12 are located symmetrically in pairs and inserted to the two sides of the support frames 11. The bed board unit 20 is put on the bed frame unit 10 and includes multiple main boards 21. The multiple main boards are foldable with respect to each other along the longitudinal direction “L” of the foldable bed assembly. The bed board unit 20 includes multiple wing boards 22 which are located in a row along the longitudinal direction “L” of the foldable bed assembly. The multiple wing boards 22 are respectively located at least one lateral side of the multiple main boards 21 corresponding thereto. Wherein, the wing boards 22 are foldable with respect to the main boards correspondingly and along the transversal direction “T” of the foldable bed assembly. Wherein, when the bed frame unit 10 and the bed board unit 20 are expanded, the multiple support frames 11 support undersides of the multiple main boards 21 correspondingly, and the multiple wing support members 12 support undersides of the multiple wing boards 22 correspondingly. Gong further, when folding the foldable bed assembly, the wing support members 12 are retracted toward the support frames 11 to reduce the width of the bed frame unit 10. The wing boards 22 are folded toward and overlapping on the top of the main boards 21 so as to reduce the width of the bed board unit 20. The support frames 11 and the main boards 21 carrying with the wing boards 22 are folded along the longitudinal direction “L” of the foldable bed assembly as disclosed in FIGS. 7, 8 . When in use, the wing support members 12 are extended from the support frames 11 to increase the width of the bed frame unit 10. The wing boards 22 are pivotably expanded relative to the main boards 21 until the wing boards 22 are positioned horizontally so as to increase the width of the bed board unit 20. The support frames 11 support the main boards 21, and the wing support members 12 support the wing boards 22 as shown in FIG. 3 . One method for folding the foldable bed assembly of the present invention is: (a1) firstly the multiple wing boards 22 being folded toward tops of the multiple main boards 21 correspondingly; (a2) secondly the multiple wing support members 12 being retracted toward the multiple support frames 11 correspondingly, i.e. the wing support members 12 are retracted into the transverse tubes 130 correspondingly; and (a3) finally the support frames 11 together with the main boards 21 and the wing boards 22 being folded along the longitudinal direction “L” of the foldable bed assembly, so that the multiple wing boards 22 are located between the multiple main boards 21, and the multiple wing boards 22 and the multiple main boards 21 are located between the multiple support frames 11. Another method for folding the foldable bed assembly is: (b1) firstly the multiple wing boards 22 being folded toward tops of the multiple main boards 21 correspondingly; (b2) secondly the support frames 11 together with the main boards 21 and the wing boards 22 being folded along the longitudinal direction “L” of the foldable bed assembly, so that the multiple wing boards 22 are located between the multiple main boards 21, and the multiple wing boards 22 and the multiple main boards 21 are located between the multiple support frames 11; and (b3) finally the multiple wing support members 12 being retracted toward the multiple support frames 11 correspondingly, i.e. the wing support members 12 are retracted into the transverse tubes 130 correspondingly.

As shown in FIGS. 1, 2, 9 and 10 , in this embodiment, multiple transverse tubes 130 extend along the transversal direction “T” of the foldable bed assembly and are connected to the main support frames 11, so that the wing support members 12 are retractably inserted into the transverse tubes 130 and retractably extend along the transversal direction “T” of the foldable bed assembly. When reducing the size of the foldable bed assembly, the wing support members 12 are retracted into the transverse tubes 130 to reduce the width of the bed frame unit 10 and the support frame 11. As shown in FIG. 9 , each wing support member 12 includes a cap 120 connected to the distal end thereof. The cap 120 is made by plastic or rubber to prevent the wing support members 12 from cutting users. The caps 120 also position the wing support members 12 when the caps 120 contact the transverse tubes 130. The caps 120 also provide a convenient grab when the users pull out the wing support members 12.

As shown in FIGS. 9 and 10 , each of the transverse tubes 130 includes at least one engaging hole 132, and each wing support member 12 includes a resilient member 121 and an engaging protrusion 122 connected to the resilient member 121. The resilient member 121 is biased in the tubular wing support member 12 corresponding thereto, and the engaging protrusion 122 of resilient member 121 protrudes beyond the wing support member 12 corresponding thereto by the elastic force of the resilient member 121 and inserted into the at least one engaging hole 132 of the transverse tube 130 corresponding thereto. In one embodiment, each transverse tube 130 includes two engaging holes 132, when the wing support member 12 is completely received in the transverse tube 130, the engaging protrusion 122 is inserted through one of the two engaging holes 132. When the wing support member 12 extends from the transverse tube 130 and reaches the position where the wing support member 12 is sufficiently support the wing board 22, the engaging protrusion 122 is inserted through the other one of the two engaging holes 132.

As shown in FIGS. 1, 3 , each of the wing boards 22 includes at least one hinge member 23 pivotably connected to at least one lateral side of the main board 21 corresponding thereto. In this embodiment, the hinge member 23 is a hinge. The wing boards 22 each are pivotable about the at least one hinge member 23 and toward the main board 21 corresponding thereto, such that each of the wing boards 22 is foldable with respect to the main board 21 corresponding thereto and along the transversal direction of the foldable bed assembly.

Preferably, as shown in FIG. 11 , the hinge member 23, in this embodiment, includes a strip 231 which is foldable and non-extendable. The strip 231 includes two half portions 230 which are formed with each other and respectively adhered to and riveted to the main board 21 and the wing board 22 corresponding thereto, such that the wing board 22 is pviotable about a separation line 233 between the two half portions 230 and toward the main board 21. An indication line 232 is formed between the two half portions 230 and identically located along the separation line 233, and is used to be in alignment with two respective facing sides between the main board 21 and the wing board 22. The strip 231 replaces the hinge to prevent from being hooked to the mattress.

As shown in FIGS. 1 and 3-6 , there are four main boards 21 which are located along the longitudinal direction “L” of the foldable bed assembly in sequence. The first and the fourth main boards 21 have the same area, and the second and the third main boards 21 have the same area. The area of the first and the fourth main boards 21 is larger than that of the second and the third main boards 21.

As shown in FIGS. 1 and 3 , the multiple wing support members 12 are respectively and symmetrically located on two opposed lateral sides of the multiple support frames 11 in pairs. The multiple wing boards 22 are respectively and symmetrically located on two opposed lateral sides of the multiple main boards 21 in pairs.

As shown in FIGS. 1, 3 to 6 , the widths “W2” in the transversal direction “T” of the foldable bed assembly of the two wing boards 22 on the two opposed lateral sides of each main board 21 are identical. The areas “A2” of the two wing boards 22 on the two sides of each main board 21 are identical. The ratio between the width “W2” in the transversal direction “T” of the foldable bed assembly of each of the two wing boards 22 and the width “W1” in the transversal direction “T” of the foldable bed assembly of each main board 21 is between ⅙ to ½. The ratio can be adjusted according practical use, such as single beds and double beds. The ratio between the area “A2” of each of the two wing boards 22 and the area “A1” of each main board 21 is between ⅙ to ½.

As shown in FIGS. 1 to 6 , each support frame 11 supports two main boards 21 which are folded along the longitudinal direction “L”, and each support frame 11 includes multiple legs 14 removably connected to the underside thereof. A top of each support frame 11 is pivotably connected at least one angle adjustment frame 13. In one embodiment, there are two support frames 11 each have two angle adjustment frames 13. Each angle adjustment frame 13 is fixed one of the multiple main boards 21. Each support frame 11 has a large angle adjustment frame 13 and a small angle adjustment frame 13 on the top thereof. The large angle adjustment frame 13 is connected to the main board 21 having large area, and the small angle adjustment frame 13 is connected to the main board 21 having small area. A driving unit 15 is pivotably connected between the support frame 11 and the angle adjustment frame 13 correspondingly. The driving unit 15 drives the angle adjustment frame 13 to rotate with respect to the multiple support frame 11 along an axial line parallel to the transversal direction of the foldable bed assembly, i.e. each main board 21 has a driving unit 15 connected thereto, and the driving unit 15 drives the angle adjustment frame 13 to pivot the wing support member 11 along the longitudinal direction “L” of the foldable bed assembly so as to make inclination adjustment of the main board 21. In this embodiment, the wing support members 12 connected to the support frame 11 with the angle adjustment frame 13 are located symmetrically in pairs on the two opposed lateral sides of the angle adjustment frame 13. In other words, the transverse tube 130 is located on the angle adjustment frame 13 so that the wing support member 12 is transversely inserted into the transverse tube 130 on the angle adjustment frame 13.

As shown in FIGS. 1 and 3 , when the bed board unit 20 is expanded relative to the bed frame unit 10, the multiple wing support members 12 respectively support the underside of the multiple wing boards 22 so that the wing support members 12 support the pressure applied to the bed frame unit 10. When the bed board unit 20 is folded relative to the bed frame unit 10, the legs 14 are removed, and the wing boards 22 are folded toward the main boards 21. Each wing support member 12 is retracted into the transverse tube 130 corresponding thereto to reduce the width of the bed frame unit 10. As shown in FIGS. 4 to 6 , by the pivotal member between the two support frames 11 and a proper force, the two support frames 11 and the four main boards 21 are folded relative to each other to fold the foldable bed assembly in the longitudinal direction “L” so as to form the folded status as shown in FIGS. 7 and 8 .

As shown in FIGS. 7 and 8 , each support frame 11 is put on with two main boards 21, the multiple wing support members 12 are located two opposed lateral sides of the multiple support frames 11 corresponding thereto, and two opposed lateral sides of each main board 21 are foldably connected with two wing boards 22. When the foldable bed assembly is in the folded status, the top of each main board 21 is overlapped with two wing boards 22, the surrounding (outer) contour lines of the two wing boards 22 projected on a first plane are inside the surrounding (outer) contour lines of the corresponding main board 21 projected on the first plane. The surrounding (outer) contour lines of every two main boards 21 put on the same one support frame 11 projected on a second plane are overlapped and form in a rectangle R1, and the ratio between the length L1 of the long side and the length L2 of the short side of the rectangle R1 is between 1˜1.1, i.e. L1/L2 is between 1˜1.1, preferably L1/L2 is between 1˜1.05.

As shown in FIGS. 1 and 2 , the angle adjustment frame 13 includes the multiple transverse tubes 130 in the transversal direction “T” and multiple longitude tubes 131 in the longitudinal direction “L”. The two adjacent transverse tubes 130 with a small distance formed therebetween each have a pivotal end formed to each of two ends thereof. Each longitude tube 131 is connected between the two adjacent transverse tubes 130 with a large distance formed therebetween.

While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention. 

What is claimed is:
 1. A foldable bed assembly comprising: a bed frame unit having multiple support frames; the multiple support frames being foldable with respect to each other along a longitudinal direction of the foldable bed assembly; multiple wing support members connected to the bed frame unit and located in a row along the longitudinal direction of the foldable bed assembly; wherein, the multiple wing support members being located at least one lateral side of the multiple support frames corresponding thereto, and the multiple wing support members retractably located along a transversal direction of the foldable bed assembly, and a bed board unit put on the bed frame unit and including multiple main boards; the multiple main boards being foldable with respect to each other along a longitudinal direction of the foldable bed assembly; the bed board unit including multiple wing boards which are located in a row along the longitudinal direction of the foldable bed assembly; the multiple wing boards respectively located at least one lateral side of the multiple main boards corresponding thereto; wherein the wing boards being foldable with respect to the main boards correspondingly and along a transversal direction of the foldable bed assembly; wherein when the bed frame unit and the bed board unit are expanded, the multiple support frames support undersides of the multiple main boards correspondingly, and the multiple wing support members support undersides of the multiple wing boards correspondingly.
 2. The foldable bed assembly as claimed in claim 1, wherein multiple transverse tubes extend along the transversal direction of the foldable bed assembly and are connected to the multiple support frames correspondingly; the multiple wing support members are retractably inserted into the transverse tubes correspondingly and retractably extend along the transversal direction of the foldable bed assembly.
 3. The foldable bed assembly as claimed in claim 2, wherein each of the transverse tubes includes at least one engaging hole, each of the multiple wing support members includes a resilient member and an engaging protrusion connected to the resilient member; the resilient member is biased in each of the multiple wing support members corresponding thereto, the engaging protrusion of the resilient member protrudes beyond each of the multiple wing support members corresponding thereto by an elastic force of the resilient member and inserted into the at least one engaging hole of the transverse tube corresponding thereto.
 4. The foldable bed assembly as claimed in claim 1, wherein each of the multiple wing boards includes at least one hinge member pivotably connected to the at least one lateral side of each of the multiple main boards corresponding thereto, such that each of the multiple wing boards is pivotable about the at least one hinge member and toward each of the multiple main boards corresponding thereto, and such that each of the multiple wing boards is foldable with respect to each of the multiple main boards corresponding thereto and along the transversal direction of the foldable bed assembly.
 5. The foldable bed assembly as claimed in claim 4, wherein the at least one hinge member includes at least one strip which includes two half portions which are formed with each other and respectively adhered to and riveted to each of the multiple main boards and each of the multiple wing boards corresponding thereto, such that each of the multiple wing boards is pviotable about a separation line between the two half portions and toward each of the multiple main boards corresponding thereto.
 6. The foldable bed assembly as claimed in claim 5, wherein an indication line is formed between the two half portions and identically located along the separation line, and located in alignment with two respective facing sides between each of the multiple main boards and each of the multiple wing boards corresponding thereto.
 7. The foldable bed assembly as claimed in claim 1, wherein the multiple wing support members are located two opposed lateral sides of the multiple support frames corresponding thereto; two of the multiple wing boards are respectively and pivotably connected to two opposed lateral sides of each of the multiple main boards, and are foldable with respect to each of the multiple main boards along the transversal direction of the foldable bed assembly.
 8. The foldable bed assembly as claimed in claim 7, wherein the two wing support members on the two opposed lateral sides of each of the multiple support frames are located symmetrically to each other; the two wing boards on the two sides of each of the multiple main boards are located symmetrically to each other; widths in the transversal direction of the foldable bed assembly of the two wing boards on the two opposed lateral sides of each of the multiple main board are identical.
 9. The foldable bed assembly as claimed in claim 7, wherein a ratio between the width in the transversal direction of the foldable bed assembly of each of the two wing boards and a width in the transversal direction of the foldable bed assembly of each of the multiple main boards is between ⅙ to ½.
 10. The foldable bed assembly as claimed in claim 1, wherein the underside of each of the multiple wing boards is supported by at least two of the multiple wing support members.
 11. The foldable bed assembly as claimed in claim 1, wherein a top of each of the multiple support frames is pivotably connected at least one angle adjustment frame; the angle adjustment frame is mounted with one of the multiple main boards; a driving unit is pivotably connected between one of the multiple support frames and the angle adjustment frame correspondingly; the driving unit drives the angle adjustment frame to rotate with respect to the corresponding support frame along an axial line parallel to the transversal direction of the foldable bed assembly.
 12. The foldable bed assembly as claimed in claim 11, wherein multiple transverse tubes extend along the transversal direction of the foldable bed assembly and are connected to the at least one angle adjustment frame correspondingly; the multiple wing support members are retractably inserted into the transverse tubes correspondingly and retractably extend along the transversal direction of the foldable bed assembly.
 13. The foldable bed assembly as claimed in claim 12, wherein the underside of each of the multiple wing boards is supported by at least two of the multiple wing support members.
 14. The foldable bed assembly as claimed in claim 1, wherein when the foldable bed assembly is to be folded completely, the multiple wing boards are firstly folded toward tops of the multiple main boards correspondingly, the multiple wing support members are secondly retracted toward the multiple support frames correspondingly, and the multiple support frames together with the multiple main boards and the multiple wing boards are finally folded along the longitudinal direction of the foldable bed assembly, so that the multiple wing boards are located between the multiple main boards, and the multiple wing boards and the multiple main boards are located between the multiple support frames.
 15. The foldable bed assembly as claimed in claim 1, wherein each support frame is put on with two main boards, and two opposed lateral sides of each main board are respectively and foldably connected with one wing board; wherein when the foldable bed assembly is in a completely folded status, one top of each main board is overlapped with two wing boards, surrounding contour lines of the two wing boards projected on a first plane are inside surrounding contour lines of the corresponding main board projected on the first plane; surrounding contour lines of the two main boards put on the same one support frame projected on a second plane are formed in a rectangle and correspondingly overlapped on four sides of the rectangle, and a ratio between lengths of a long side and a short side of the rectangle is between 1˜1.1.
 16. The foldable bed assembly as claimed in claim 1, wherein the ratio between the lengths of the long side and the short side of the rectangle is between 1˜1.05.
 17. A folding method for a foldable bed assembly, the foldable bed assembly comprising a bed frame unit and a bed board unit; the bed frame unit having multiple support frames; the multiple support frames being foldable with respect to each other along a longitudinal direction of the foldable bed assembly; multiple wing support members connected to the bed frame unit and located in a row along the longitudinal direction of the foldable bed assembly; wherein, the multiple wing support members being located at least one lateral side of the multiple support frames corresponding thereto, and the multiple wing support members retractably located along a transversal direction of the foldable bed assembly; the bed board unit put on the bed frame unit and including multiple main boards; the multiple main boards being foldable with respect to each other along a longitudinal direction of the foldable bed assembly; the bed board unit including multiple wing boards which are located in a row along the longitudinal direction of the foldable bed assembly; the multiple wing boards respectively located at least one lateral side of the multiple main boards corresponding thereto; wherein the multiple wing boards being foldable with respect to the multiple main boards correspondingly and along a transversal direction of the foldable bed assembly; wherein when the bed frame unit and the bed board unit are expanded, the multiple support frames support undersides of the multiple main boards correspondingly, and the multiple wing support members support undersides of the multiple wing boards correspondingly; wherein, the method comprising the steps of: firstly the multiple wing boards being folded toward tops of the multiple main boards correspondingly; secondly the multiple wing support members being retracted toward the multiple support frames correspondingly, and finally the support frames together with the main boards and the wing boards being folded along the longitudinal direction of the foldable bed assembly, so that the multiple wing boards are located between the multiple main boards, and the multiple wing boards and the multiple main boards are located between the multiple support frames.
 18. The method as claimed in claim 17, wherein, wherein, each support frame is put on with two main boards, the multiple wing support members are located two opposed lateral sides of the multiple support frames corresponding thereto, and two opposed lateral sides of each main board are respectively and foldably connected with one wing board; wherein when the foldable bed assembly is in a completely folded status, one top of each main board is overlapped with two wing boards correspondingly, surrounding contour lines of the two wing boards projected on a first plane are inside surrounding contour lines of the corresponding main board projected on the first plane; surrounding contour lines of every two main boards put on the same one support frame projected on a second plane are formed in a rectangle and correspondingly overlapped on four sides of the rectangle, and a ratio between lengths of a long side and a short side of the rectangle is between 1˜1.1.
 19. A folding method for a foldable bed assembly, the foldable bed assembly comprising a bed frame unit and a bed board unit; the bed frame unit having multiple support frames; the multiple support frames being foldable with respect to each other along a longitudinal direction of the foldable bed assembly; multiple wing support members connected to the bed frame unit and located in a row along the longitudinal direction of the foldable bed assembly; wherein, the multiple wing support members being located at least one lateral side of the multiple support frames corresponding thereto, and the multiple wing support members retractably located along a transversal direction of the foldable bed assembly; the bed board unit put on the bed frame unit and including multiple main boards; the multiple main boards being foldable with respect to each other along a longitudinal direction of the foldable bed assembly; the bed board unit including multiple wing boards which are located in a row along the longitudinal direction of the foldable bed assembly; the multiple wing boards respectively located at least one lateral side of the multiple main boards corresponding thereto; wherein the multiple wing boards being foldable with respect to the multiple main boards correspondingly and along a transversal direction of the foldable bed assembly; wherein when the bed frame unit and the bed board unit are expanded, the multiple support frames support undersides of the multiple main boards correspondingly, and the multiple wing support members support undersides of the multiple wing boards correspondingly; wherein, the method comprising the steps of: firstly the multiple wing boards being folded toward tops of the multiple main boards correspondingly; secondly the support frames together with the main boards and the wing boards being folded along the longitudinal direction of the foldable bed assembly, so that the multiple wing boards are located between the multiple main boards, and the multiple wing boards and the multiple main boards are located between the multiple support frames, and finally the multiple wing support members being retracted toward the multiple support frames correspondingly.
 20. The method as claimed in claim 19, wherein, each support frame is put on with two main boards, the multiple wing support members are located two opposed lateral sides of the multiple support frames corresponding thereto, and two opposed lateral sides of each main board are respectively and foldably connected with one wing board; wherein when the foldable bed assembly is in a completely folded status, one top of each main board is overlapped with two wing boards correspondingly, surrounding contour lines of the two wing boards projected on a first plane are inside surrounding contour lines of the corresponding main board projected on the first plane; surrounding contour lines of every two main boards put on the same one support frame projected on a second plane are formed in a rectangle and correspondingly overlapped on four sides of the rectangle, and a ratio between lengths of a long side and a short side of the rectangle is between 1˜1.05. 